1. Technical Field of the Invention
The present invention relates to an electric discharge lamp unit which supports an electric discharge lamp.
2. Related Art
An example of the electric discharge lamp unit is disclosed in JP-A-2003-022702. In this unit, a case member and a support member are integrated with each other. The case member houses a lighting circuit for lighting an electric discharge lamp. The support member supports the electric discharge lamp. Part of the case member near the support member is made of resin having low heat conductivity. Part of the case member located far from the support member is made of metal having high conductivity. According to the electric discharge lamp unit, the heat generated from the electric discharge lamp is difficult to conduct to the entire case member, thereby suppressing the increase in temperature inside the case.
In the case member of the above electric discharge lamp unit, the part near the electric discharge lamp, which is made of resin, is heated. When convective air exists inside the case member, the heat of the case member is easily moved by the convection of air, which can easily increase the temperature of the lighting circuit.